Modular solenoid-operated dispenser

ABSTRACT

A solenoid-operated dispenser for dispensing liquid materials. The dispenser comprises a heated service module which contains static parts, a gun module which contains all of the movable parts of the dispenser, and a plug-in solenoid coil module, all three modules of which are resiliently held in an assembled relationship by a single threaded nut.

United States Patent [191 Hamilton et a1.

MODULAR SOLENOID-OPERATED DISPENSER Inventors: William M. Hamilton,Lorain; Alan B. Reighard, Bay Village; Simon Z. Tamny, Lorain, all ofOhio Nordson Corporation, Amhurst, Ohio Filed: Sept. 11, 1972 Appl. No.:287,645

Assignee:

References Cited UNITED STATES PATENTS Steel 251/139 [451 Aug. 6, 19742,546,325 3/1951 Wasserlein 251/139 2,746,022 5/1956 Gilbert 339/92 M2,761,109 8/1956 Hacker.... 339/75 P 3,159,444 12/1964 Stine 339/92 M3,161,450 12/1964 Goodenough 339/92 R 3,408,008 10/1968 Cocks 222/146 R3,430,816 3/1969 Nadherny et a1. 222/146 R 3,662,927 5/1972 Cocks222/146 HE 3,687,216 8/1972 Tracy 251/139 Prirnary ExaminerRobert B.Reeves Assistant ExaminerH. Grant Skaggs, Jr. Attorney, Agent, orFirmWood, Herron & Evans [57] ABSTRACT A solenoid-operated dispenser fordispensing liquid materials. The dispenser comprises a heated servicemodule which contains static parts, a gun module which contains all ofthe movable parts of the dispenser, and a plug-in solenoid coil module,all three modules of which are resiliently held in an assembledrelationship by a single threaded nut.

13 Claims, 3 Drawing Figures MODULAR SOLENOID-OPERATED DISPENSER Thisinvention relates to a dispenser or a gun for dispensing liquids in theform of beads, ribbons, or stripes in a desired pattern under high speedproduction conditions. More particularly, the invention relates toequipment for applying molten adhesives or so-called hot melts tosubstrates used in packaging, sealing or assembling a variety ofproducts.

Liquid adhesives, or so-called hot melts, are commonly used where thereis a need for a very short setting time for the material to set up andbond together two parts of a package or'two parts of an assembly.Typically, they are solid at room temperature and must be heated beforethey become molten so that they can be supplied to and dispensed from agun. When heated to molten form, the materials change to a liquid whichmay be supplied to a dispensing gun at a relatively high pressure andthen dispensed from the nozzle of the gun in the form of a continuousbead or ribbon or an intermittent deposit. The flow of material from thegun is controlled by a valve located internally of the gun adjacent thenozzle orifice.

A common production problem encountered with hot melt dispensing guns inhigh production facilities is that of interupting the productionfacility for relatively long periods of time in order to clean the gunof hot melt material which has become lodged therein or to replace wornout parts. Generally, cleaning requires disconnection of the servicelines including the electrical service lines to the heater of the gun,disconnection of the liquid supply lines for supplying the moltenmaterial to the gun, and disconnection of the power lines for operatingthe gun. If the gun is a pneumatically operated gun, the power line isan air line to the gun; and if the gun is solenoid-operated, the powerline is an electrical one. After disconnection of all lines, the gungenerally must be broken apart in order to disconnect it from itsmounting so as to enable a new or clean gun to replace it. All of thisdisconnection and disassembly is generally time-consuming and expensivebecause of the resulting loss of a production facility on which the gunis one relatively small component.

in U.S. Pat. No. 3,570,725, issued Mar. 16, 1971, and assigned to theassignee of this application, there is disclosed a modular type ofpneumatically operated gun in which the gun may be removed from aservice module as a separate unit and replaced without any timeconsumingdisconnection of the service lines and disassembly of the gun. Thatmodular gun has been well received in hot melt production facilities andhas eliminated many of the problems set forth hereinabove. There isstill, though, a need for a solenoid-operated modular gun to accomplishthe same objectives and eliminate the time-consuming disassembly andreassembly problem normally associated with the cleaning and replacementof solenoid-operated hot melt dispensing guns in high speed productionfacilities.

It has therefore been one objective of this invention to provide amodular solenoid-operated dispensing system in which the gun portion ofthe dispenser may be easily and quickly replaced in the event that thegun portion needs to be cleaned or a component needs to be replaced.

Still another object of this invention has been to provide asolenoid-operated dispensing apparatus for dispensing hot melt orviscous liquids in which the solenoid coil of the gun may be easily andquickly replaced in the event that it fails while the remainder of thegun and system is fully operative.

The invention of this application which accomplishes these objectivescomprises a three-module dispensing apparatus made from a servicemodule, a gun module, and a solenoid module. All three modules areresiliently held in an assembled relation by a single threadedconnector. The service module houses all of the essentially staticcomponents of the dispenser and includes a solenoid plug-in connector aswell as an electrical heater for heating the service module andsubsequently transmitting heat through contacting surfaces to the gunmodule so that the molten material contained in the gun remains in themolten state. The gun module contains all the movable components of thedispensing apparatus and is generally tubular in configuration. Overthis tubular gun module the plug-in solenoid coil module is mounted andis resiliently held in an assembled relation by a single threadedconnector which also holds the gun module mounted within an aperture ofthe service module.

The primary advantage of this modular construction of solenoid-operateddispenser with its plug-in solenoid electrical lead connection is thatit enables the solenoid module to be quickly replaced in the event thatit fails or the gun module to be easily and quickly replaced in theevent that it becomes clogged or breaks down because of excessively wornparts. In unionized shops where union rules require an electrician tomake all electrical repairs, it generally eliminates the need for theelectrician to make this repair because of nonelectrical repairmen beingpermitted to pull electrical plugs but not connect or disconnect othertypes of electrical connectors. After replacement of a worn or cloggedgun with a new clean one, or replacement of a failed coil, the failedcomponent may be torn down and rebuilt without interruption of aproduction facility upon which the dispensing apparatus had previouslybeen in use. This construction also has the advantage of facilitatingrepair and cleaning of the dispensing apparatus.

These and other objects and advantages of this invention will be morereadily apparent from the following description of the drawingsillustrating one preferred embodiment of the invention in which:

FIG. 1 is an exploded perspective view of a dispensing apparatusincorporating the invention of this application;

FIG. 2 is a cross sectional view of the apparatus; and

FIG. 3 is a cross sectional view of a portion of the dispensingapparatus but illustrating a second modification of solenoid plug-inelectrical connector.

Referring to FIG. 1, it will be seen that the dispenser 10 of thisapplication is assembled from three modules which are easily assembledand disaaaembled for purposes of cleaning or repairing the unit.Specifically, this dispenser 10 comprises a service module 11, a gunmodule 12, and'a solenoid coil module 13. These three modules are allresiliently held in an assembled relation by a resilient washer 14a anda single nut 14 threaded over one end 15 of the gun module 12, as isexplained more fully hereinafter.

The service module 11 serves as a mounting block for the gun andsolenoid coil modules as well as for an electrical control enclosure 16.This service module 11 is generally fixedly mounted, by means not shown,upon a slide block or some other fixed fastening located in apredetermined location relative to a substrate upon which molten liquidmaterial is dispensed from the gun.

The service module 11 is comprised of a stepped block 17 which has twovertical bores through it. One of these bores 18 is counterbored and isadapted to receive an electric heating element 19. The other borereceives and supports the gun module 12.

Electrical power to the solenoid coil 20 is supplied via electricalleads 21 which are housed within the conventional electrical enclosureor so-called junction box 16. This box is fixedly mounted upon the topof the service block 17. The enclosure within the box 16 also houses anelectrical thermostat 22 which controls the flow of electric power tothe heater 19 and consequently determines the temperature of the block17. Heat from the block 17 in turn is transmitted through the contactingsurfaces of the service module block 17 and the gun module 12 intomolten material contained interiorly of the gun.

It is to be noted that the electrical leads 21 from the junction boxterminate in an electrical plug 23. This plug 23 fits within a recess 24formed in the service module block 17. In order to prevent the plug frommoving vertically in the recess 24 while still permitting it to beinserted horizontally, the plug 23 has a flange 25 which fits withintransverse slots 26 formed in the service module recess 24.Consequently, the plug 23 may be inserted and removed from the servicemodule by sliding it horizontally but it is locked by the flange 25against vertical displacement.

The gun module 12 comprises a cylinder assembly 30, a nozzle assembly31, a valve 32 for controlling the flow of pressurized molten materialfrom the nozzle 31, and a valve plunger 33 for controlling actuation ofthe valve 32.

The cylinder assembly is made from four components, all of which arebrazed together to form a sealed and joined unit. These componentscomprise an annular flange 35, a spring chamber sleeve 36, a nonmagneticplunger guide sleeve 37, and a magnetic inlet fitting 38. The springchamber sleeve 36 has a through bore 40 which is counterbored at thelower end and provides a large open chamber for the reception of a valvecontrol spring 41. This bore 40 is also counterbored at its upper end asindicated at 42 so as to provide a seat for the lower end of the plungerguide sleeve 37. At its upper end, the plunger guide sleeve 37 receivesthe lower end 45 of the molten material inlet fit ting 38. There ispreferably a conventional, copper shading ring 46 mounted within anannular recess machined from the lower end of the inlet fitting 38. Theupper end of the inlet fitting is externally threaded for reception ofthe nut 14 which resiliently holds the three modules in an assembledrelation, as is explained more fully hereinafter.

The nozzle assembly 31 of the dispensing gun is conventional andcomprises a radially flanged gun seat through which there extends anaxial bore 50. This axial bore is counterbored so that the lower smalldiameter end section may receive and be brazed to a carbide valve seat51. The radial flange 53 of the nozzle gun seat is bolted to the flange35 of the cylinder assembly by machine screws 55. There is preferably ametal ring 56 located between the lower end of the cylinder At its upperend the needle 57 is externally threaded and is received within aninternally threaded bore 65 of the plunger. A lock nut 66 secures theneedle in an axially adjusted position within the plunger.

Intermediate its ends, the needle supports a spring collar 70. Thiscollar has a central hub 71 threaded over the threaded section of theneedle and four arms 72 which extend radially from the hub 71 to supportthe lower end of the compression spring 41. At its upper end this springrests against a shoulder 73 in the bore of the spring chamber sleeve 36.There is preferably a lock nut 75 threaded over the needle to lock thespring collar 70 in an adjusted position.

The plunger 33 is made from a magnetic stainless steel or other magneticferrous material so that it functions as the armature of the solenoidcoil 20 within the cylinder. A gap between the lower end of the inletfitting 38 and the top surface of the plunger permits the plunger to bemoved upwardly by magnetic flux of the solenoid coil 20. When theplunger is in its uppermost position, the valve 32 is open so thatpressurized molten material contained within the valve chamber 50 of thenozzle may exit through the valve passage 59.

In order for the molten material supplied to the gun via the inletfitting 38 to flow through the axial passage 81 of the fitting 38downwardly to the valve chamber 50, there are four radial grooves 84 andfour intersecting longitudinal grooves 85 machined from the surface ofthe plunger. The radial grooves 84 in the top surface of the plunger areaxially aligned with and intersect the longitudinal grooves 85 in theperipheral surface of the plunger so that each groove forms a continuousflow path along the exterior of the plunger from the lower end of thepassage 81 into the spring changer 40 of the sleeve 36 and subsequentlyinto the valve changer 50 of the nozzle assembly 31.

The solenoid coil module 13 comprises a tubular spool of Teflon or asimilar dielectric material upon 7 which the wire of the coil 20 iswound. The ends of this wire terminate in a male plug 89, the electricalprongs of which are adapted to be received into the female receptaclesof the service module mounted plug 23. Consequently, when the two plugsare electrically interconnected, an electrical connection is madebetween the leads 21 in the junction box and the windings of the coil20. The two plugs are so positioned that assembly of the solenoid overthe cylinder of the gun and onto the service module automatically makesthis electrical connection. Similarly, removal of the solenoid modulefrom over the cylinder of the gun module automatically breaks theelectrical connection.

In order to form the plug 89 on the solenoid coil module, the wound coiland spool are placed in an injection mold and encased in a sheathing ofplastic 88. In the course of applying the molded plastic sheating 88,the plug 89 is simultaneously molded onto the coil. The plastic encasedcoil is then placed in a magnetic metal enclosure 87. The enclosurecomprises a steel sleeve 91 over which there is fitted a steel cap 92and a lower flux retainer disc 93. The disc has a cutout recess 94 onone side through which the plug 89 extends.

The lower retainer flux ring 93, the sleeve 91, and the cap 92 are allsealed around the coil 20 so as to form a complete subassembly which maybe assembled over the cylinder of the gun or removed therefrom as acomplete unit. This module 13 is held in an assembled relation over thebarrel by the nut 14 threaded over the end of the fitting 15 and overthe resilient Washer 140. The

purpose of the resilient washer 14a is to accommodate relative thermaldeflections among the service module 11, the gun 12, and solenoid module13.

In operation, if the gun should become clogged or should fail for anyreason, all that is required to remove it from the service module 11 soas to permit its replacement on the service module is to disconnect thesupply hose and remove the nut 14 and resilient washer 14a from over theinlet fitting of the gun barrel. Upon removal of this nut and resilientwasher, the complete gun may be dropped downwardly through the bore 96.Alternatively, if the coil should fail, all that is required to removeit is to remove this same nut 14 and resilient washer 14a and lift themfrom over the cylinder, and, in the process, disconnect the electricalconnector of the solenoid with the leads 21. The solenoid coil modulemay then be replaced or the gun module may be replaced with a minimum oflost production time. After the gun module or the solenoid module hasbeen removed from the service module, cleaning or disassembly may takeplace while the production line upon which the dispensing apparatusoperates continues to function.

It is also to be noted that when one solenoid replaces another theplastic-encased coil may be removed and replaced in the metal housing 87or encasement. This construction thus minimizes the cost of replacing aburnt out coil.

Referring now to FIG. 3, there is illustrated a second modification ofplug-in connector for electrically connecting the solenoid module to theelectrical leads 21 from the electrical junction box 16. Except for thedifference in this electrical connection, though, the dispenser of FIG.3 is identical to the dispenser of FIGS. 1 and 2 and, accordingly,identical components have been given identical numerical designations.

The solenoid module 13 of this modification of the dispenser comprisesthe same solenoid coil 20 wound upon the spool 90 as in FIG. 1. Theplastic encasement 88 of the coil, though, has a female electricalconnector plug 98 molded onto the top of the encasement 88 rather than amale connection on the bottom as in the FIG. 1 modification. Thismodification also differs in that the male plug 99 attached to the leads21 is mounted within a washer 100 which is attached to the nut 14. Thewasher 100 is swaged onto a peripheral recess 101 of the nut 14 so thatit rotates freely upon the nut. The plug 99 is fixedly mounted upon oneside of the washer so that in the course of rotating the nut 14 toremove it from the fitting 38, the nonrotating washer 100 and attachedplug 99' are automatically disconnected from the female plug 98 of thesolenoid module 13. Similarly, in the course of threading the nut ontothe fitting 38, the electrical connection is automatically made betweenthe two plugs 98 and 99.

While we have described only a single preferred embodiment of ourinvention, persons skilled in this art will appreciate changes andmodifications which may be made without departing from the spirit of ourinvention. Therefore, we do not intend to be limited except by the scopeof the following appended claims.

Having described our invention, we claim:

1. Apparatus for dispensing a liquid from a pressurized sourcecomprising i a service module having essentially only static parts, saidservice module including a mounting block having a gun module contactingsurface of substantial area, said mounting block being adapted to besecured to a support, readily removable gun module attachable to andmountable upon said service module mounting block, said gun moduleincluding essentially all of the movable parts of said dispensingapparatus, said gun module including a discharge nozzle and a valve forcontrolling flow of viscous liquid from said nozzle, said gun modulefurther including a cylinder and a movable plunger mounted within saidcylinder, said plunger being operatively connected to said valve so asto effect opening and closing of said valve upon actuation of saidplunger, said gun module having a service module mounting blockcontacting surface of substantial area,

heater means contained within said service module for heating saidservice module mounting block, said service module mounting block beingoperable to transmit heat through said contacting surface into said gunmodule so as to heat liquid contained within said gun module, and

a solenoid coil module mounted over said cylinder of said gun module,said solenoid coil module including an electrical solenoidcoil forcontrolling movement of said plunger within said cylinder,

said solenoid coil module being removable and replaceable on saiddispensing apparatus without disassembly of said gun module and said gunmodule being removable and replaceable on said service module withoutdisassambly of said gun module,

said solenoid coil module and said gun module being jointly secured tosaid service module mounting block by a single fastening element, and

said solenoid coil being encased within a housing, said solenoid coilmodule including an electrical plug extending through said housing, saidelectrical plug being adapted to make an electrical connection with asource of electrical power when said solenoid coil module is assembledwith said service block module and said gun module.

2. The dispensing apparatus of claim 1 in which said heater means is anelectrical heater mounted within said service module mounting block,said service module further including a thermostat for controlling thefiow of electrical power to said electrical heater.

3. The dispensing apparatus of claim 1 in which said service modulemounting block has an aperture therein for the reception of said gunmodule, said gun module being mounted within said aperture, with atleast a portion of said cylinder extending outwardly from said aperture,said solenoid coil module being mounted over said cylinder outwardly ofsaid aperture.

4. The dispensing apparatus of claim 1 in which said fastening elementis a threaded element.

5. The apparatus of claim 4 in which said threaded element has anelectrical plug attached thereto, said plugs being so positioned thatassembly of said modules and said threaded element automatically effectselectrical interconnection of said plugs.

6. The'apparatus of claim 1 in which said service block module has anelectrical plug mounted thereon, said plugs being so positioned thatassembly of said solenoid coil module, said gun module, and said serviceblock module automatically effects electrical interconnection of saidplugs.

7. The dispensing apparatus of claim 1 in which said solenoid coil isencased in a molded plastic encasement,'said plastic encasement havingsaid electrical plug formed as an integral portion thereof.

8. Apparatus for dispensing a viscous liquid from a pressurized sourcecomprising a service block module having essentially only staticparts,said service block module including a mounting block adapted to besecured to a support, heating means contained within said service modulemounting block, readily removable gun module attachable to and mountableupon said service module mounting block, said gun module includingessentially all of the movable parts of said dispensing apparatus, saidgun module including a discharge nozzle, a valve for controlling flow ofviscous liquid from said nozzle, and spring means for biasing said valveto a closed position, said gun module further including a cylinder and amovable plunger mounted within said cylinder, said plunger beingoperatively connected to said valve so as to effect opening and closingof said valve upon actuation of said plunger, a solenoid coil modulemounted over said cylinder of said gun module, said solenoid coil moduleincluding an electrical solenoid coil for controlling movement of saidplunger within said cylinder,

a single fastening element for jointly securing said solenoid coilmodule and said gun module to said service module, and

said solenoid coil being encased within a housing,

said solenoid coil module including an electrical plug extending throughsaid housing, said plug being adapted to make an electrical connectionwith a source of electrical power when said solenoid coil module isassembled with said service block module and said gun module.

9. The apparatus of claim 8 in which said service block module has anelectrical plug mounted thereon, said plugs being so positioned thatassembly of said solenoid coil module, said gun module, and said serviceblock module automatically effects electrical interconnection of saidplugs.

10. The dispensing apparatus of claim 8 in which said fastening elementis a threaded element.

11. The apparatus of claim 10 in which said threaded element has anelectrical plug attached thereto, said plugs being so positioned thatassembly of said modules and said threaded element automatically effectselectrical interconnection of said plugs.

12. The dispensing apparatus of claim 8 in which said service module hasan aperture therein for the reception of said gun module, said gunmodule being mounted within said aperture with at least a portion ofsaid cylinder extending outwardly from said aperture, and said solenoidcoil module being mounted over said cylinder outwardly of said aperture.

13. The dispensing apparatus of claim 8 in which said solenoid coil isencased in a molded plastic encasement, said plastic encasement havingsaid electrical plug formed as an integral portion thereof.

1. Apparatus for dispensing a liquid from a pressurized sourcecomprising a service module having essentially only static parts, saidservice module including a mounting block having a gun module contactingsurface of substantial area, said mounting block being adapted to besecured to a support, a readily removable gun module attachable to andmountable upon said service module mounting block, said gun moduleincluding essentially all of the movable parts of said dispensingapparatus, said gun module including a discharge nozzle and a valve forcontrolling flow of viscous liquid from said nozzle, said gun modulefurther including a cylinder and a movable plunger mounted within saidcylinder, said plunger being operatively connected to said valve so asto effect opening and closing of said valve upon actuation of saidplunger, said gun module having a service module mounting blockcontacting surface of substantial area, heater means contained withinsaid service module for heating said service module mounting block, saidservice module mounting block being operable to transmit heat throughsaid contacting surface into said gun module so as to heat liquidcontained within said gun module, and a solenoid coil module mountedover said cylinder of said gun module, said solenoid coil moduleincluding an electrical solenoid coil for controlling movement of saidplunger within said cylinder, said solenoid coil module being removableand replaceable on said dispensing apparatus without disassembly of saidgun module and said gun module being removable and replaceable on saidservice module without disassambly of said gun module, said solenoidcoil module and said gun module being jointly secured to said servicemodule mounting block by a single fastening element, and said solenoidcoil being encased within a housing, said solenoid coil module includingan electrical plug extending through said housing, said electrical plugbeing adapted to make an electrical connection with a source ofelectrical power when said solenoid coil module is assembled with saidservice block module and said gun module.
 2. The dispensing apparatus ofclaim 1 in which said heater means is an electrical heater mountedwithin said service module mounting block, said service module furtherincluding a thermostat for controlling the flow of electrical power tosaid electrical heater.
 3. The dispensing apparatus of claim 1 in whichsaid service module mounting block has an aperture therein for thereception of said gun module, said gun module being mounted within saidaperture, with at least a portion of said cylinder extending outwardlyfrom said aperture, said solenoid coil module being mounted over saidcylinder outwardly of said aperture.
 4. The dispensing apparatus ofclaim 1 in which said fastening element is a threaded element.
 5. Theapparatus of claim 4 in which said threaded element has an electricalplug attached thereto, said plugs being so positioned that assembly ofsaid modules and said threaded element automatically effects electricalinterconnection of said plugs.
 6. The apparatus of claim 1 in which saidservice block module has an electrical plug mounted thereon, said plugsbeing so positioned that assembly of said solenoid coil module, said gunmodule, and said service block module automatically effects electricalinterconnection of said plugs.
 7. The dispensing apparatus of claim 1 inwhich said solenoid coil is encased in a molded plastic encasement, saidplastic encasement having said electrical plug formed as an integralportion thereof.
 8. Apparatus for dispensing a viscous liquid from apressurized source comprising a service block module having essentiallyonly static parts, said service block module including a mounting blockadapted to be secured to a support, heating means contained within saidservice module mounting block, a readily removable gun module attachableto and mountable upon said service module mounting block, said gunmodule including essentially all of the movable parts of said dispensingapparatus, said gun module including a discharge nozzle, a valve forcontrolling flow of viscous liquid from said nozzle, and spring meansfor biasing said valve to a closed position, said gun module furtherincluding a cylinder and a movable plunger mounted within said cylinder,said plunger being operatively connected to said valve so as to effectopening and closing of said valve upon actuation of said plunger, asolenoid coil module mounted over said cylinder of said gun module, saidsolenoid coil module including an electrical solenoid coil forcontrolling movement of said plunger within said cylinder, a singlefastening element for jointly securing said solenoid coil module andsaid gun module to said service module, and said solenoid coil beingencased within a housing, said solenoid coil module including anelectrical plug extending through said housing, said plug being adaptedto make an electrical connection with a source of electrical power whensaid solenoid coil module is assembled with said service block moduleand said guN module.
 9. The apparatus of claim 8 in which said serviceblock module has an electrical plug mounted thereon, said plugs being sopositioned that assembly of said solenoid coil module, said gun module,and said service block module automatically effects electricalinterconnection of said plugs.
 10. The dispensing apparatus of claim 8in which said fastening element is a threaded element.
 11. The apparatusof claim 10 in which said threaded element has an electrical plugattached thereto, said plugs being so positioned that assembly of saidmodules and said threaded element automatically effects electricalinterconnection of said plugs.
 12. The dispensing apparatus of claim 8in which said service module has an aperture therein for the receptionof said gun module, said gun module being mounted within said aperturewith at least a portion of said cylinder extending outwardly from saidaperture, and said solenoid coil module being mounted over said cylinderoutwardly of said aperture.
 13. The dispensing apparatus of claim 8 inwhich said solenoid coil is encased in a molded plastic encasement, saidplastic encasement having said electrical plug formed as an integralportion thereof.